So this happened in the presence of Canadians. 
I remember that in biography of one u-boat captain (Iron Coffins) there was also an ugly, messy execution of two German soldiers after surrender. But I guess it was like a day or two after surrender and there weren’t allies nearby.
According to this, the last battle between sailing vessels. Scroll to #3.
There were many “irregular” killings/lynchings of suspected German deserters in the last weeks and days before the surrender. I am not aware of any that occurred after May 8 (except the one mentioned before). There were, however, two cases of German POWs murdering fellow POWs who they considered “traitors”. This happened in Oklahoma in 1943 and in Arizona in 1944. The killers were sentenced to death and executed by the US military in the summer of 1945. Their graves are in the Fort Leavenworth cemetery:
→ http://www.leavenworthtimes.com/article/20110813/NEWS/308139935
Last German POW to surrender to US authorities after having escaped from a POW camp: Georg Gärtner in 1985:
Hmmm. I would have called the order a “counter attack”. 
Obviously, your mileage varies.
On August 16, 1945, the day after Japan surrendered, there were only four American airmen still alive at the Osaka Kempei Tai prison. The men were told that they were being freed and were given back their uniforms, unloaded weapons, personal effects and even their parachutes. Korean forced-laborers reported that the men were smiling and waved to them as they were leaving the camp. One even yelled that they were “going home”.
Instead the Japanese led them to the cemetery where a large hole had been dug. They were beheaded and thrown into the ditch. On top of them were piled their personal effects, along with those of the 55 Americans previously killed, and any other evidence that Americans had ever been held there.
I’m sorry, I’ve been very sick all week and haven’t been on the computer. My uncle was one of the other 55, so I am close to the subject. For some reason the government classified what occurred there, I think probably because they didn’t uncover what happened until 1947, when China and eastern Europe where falling to the communists. In the early 90’s I was able to get the declassified documents from the National Archives, and its a horrible story.
There is little on the internet concerning this, at least the last time I checked. However there was kind of a humorous story of a downed airmen who bullshitted the Japs about his knowledge of tha atomic bomb, which saved his life because he was sent to Tokyo, unlike his crewmates who were sent to Osaka. I’ll look that story up and provide a link.
If you want more cites, I have boxes of documents, some of which I’ll scan into the computer. If there are any writers out there looking for an intense story, contact me. This is a piece of history that needs to be told.
Found the link:
August 9, 1945 was the last time an atomic bomb was used in combat.
One can hope anyway.
The last looted asset returned to its proper owner - yet to be determined.